<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		
		
		<style>
			*{
				margin: 0;
				padding: 0;
			}
			#parent {
			  background: red;
			  width: 200px;
			  height: 200px;
			  /* overflow:hidden; */
			}
			#child {
			  background: green;
			  width: 50px;
			  height: 50px;
			  margin-top: 50px;
			}

		</style>
	</head>
	<body>

		<div id="parent">
			<div id="child">
				demo
			</div>
		</div>



	</body>
</html>
